Drill bit



Jame 15,1926. V I 1,589,153

u C. L. HARRALSON I DRILL IEIQIT.

Filed August 19 24 Patented dune. l5, 1926.

warren stares nane CHARLES L. HAEBALSON, 0F GAB-PER, WYQMING- :DBHIII BIT.

Application filed August 8, 18%. Serial Ito. 330,923.

My invention relates to drill bits and more particularly to the drill bits described 111 my application filed Aug. 28, 1922, Ser. No. 584,917; and the object is to provide-drill bits for drilling oil and other wells and which are provided with multiple Wings or blades which are spiral in form, making the blades slanting so that'the directlystraight lift is to some extent avoided and the bit is thus compelled to rotate in an up or down stroke, thus throwing the mud from the central part outwardly and forming a mud plaster on the Walls of the well and thus preventing the walls of the Well from caving or ravelling. With such construction the bit will not be caked with mud. One side of the bit is cleaned going downward and the other side is cleaned going upward. Another advantage is that the outer points ot the blades are approximately in the same elevation as the central part of the lower en d. of the bit and this construction makes and keeps the hole flat on the bottom and thus preventing the hole from becoming keyseafed. The bit has been shown to be highly eilicient in actual service conditions. Other objects and advantages will be fully explained in the following description and the invention will be more particularly pointed out in the claims.

Reference is had to the accompanying drawings which form a part of this application. l

Fig. 1 is a side elevation of the bit, showing the points of the blades and the spiral formation of the blades. Fig. 2 is a bottom plan view of the blades.

Similar characters of reference are-used to indicate the same parts throughout the several views.

The improved bit herein set forth is a multiple spiral blade bit and is shown provided with points 3, l, 5, and i), the points being slightly lower: than the central part of the lower surface and the points are bevoled. The blades are made in spiral form lln-oiw'hout the length ofthe bit, thus coinpelling' the bit to rotate on up or down,

strokes and at the same time avoiding a direct vertical lift. The bit has the usual.

shank connection 1. The spiral forms of the blades form spiral grooves in the bit. The object at the spiral blades or points is to keep the mud stirred and also; to make the shoulders at the upper end of the bit serve .to keep the bit vertically disposed in'the well so that it can readily be engaged by a fishing tool. T he spiral form of the blades keeps the liqliid agitated and prevents click ing with mud; and since the blades are of a uniform radius or diameter the wall of the hole will be of uniform diameter and straight.

The bit is provided with a face which has beveled cutting edges which project out of the plane of the face at the external position. In Fig. 2, 7 indicates the water courses of the spiral form of the bit. The spiral torm begins adjacent to the cutting edges and extends the whole length of the bit. After the bit has been formed, the faces of the blades. have to be'dressed or sharpened in any suitable manner; The bit may be rolled, or forged, or cast of suitable metal.

than a complete turn throughout the length of the blade.

2.1%. cable tool impact drill bit having more than two integral spiral blades or wings and provided with a wrenchsquare, a collar, and a tool joint at one end, said spiral blades or wings extending back from the cutting end to the wrench square, and making less than a complete turn throughout the length of the blade.

It must be understood that this.

. In testimony whereof, I set my hand, this I 5th day of August, 1924;.

CHARLES L. HARRALSON. 

